Multilateration applied to airport vehicles management systems: the Agile Trasponder

This paper is focused on the implementation of an innovative vehicles surveillance system using the 1090 MHz channel. SSR (secondary surveillance radar) mode S (selective) exploitation in high traffic environment calls for enhancing communication capacity. In the multilateration and ADS-B applications, the presence of both SSR mode S replies and squitter makes the superimposition of 1090 MHz signals probable. In Sect. II it is shown that these limitations in SSR signals analysis and decoding can be mitigated by exploiting the ICAO tolerance of the transponder transmission carrier frequency, whose central value has to be within the interval between 1087 and 1093 MHz (reduced to 1090plusmn1 MHz later). The AVMS (airport vehicles management system) project enables the implementation of A-SMGCS functionalities. For the management of the large flat of airport service vehicles we propose the use of adjacent frequency channels for vehicular mode S transmissions to avoid frequency signals superimposition with airbornes replies. A receiver equipped with selective digital filtering allows to separate the airborne channel by the vehicular one. In section III we show the channel capacity improvement, then we exploit the detection and the TOA estimation of frequency agility environment signals. Finally in section IV is analyzed the compliance with the EUROCAE requirements matching and conclusion are drawn